Optical disc, optical disc recording and reproducing apparatus, and optical disc recording and reproducing method

ABSTRACT

An optical disc recorder and player enable entry points to be set as desired in a plurality of logically meaningful reproduction paths to skip to various points as desired in any of the possible paths. The optical disc recorder and player use information about a plurality of independent reproduction paths, and management information having a plurality of reproduction entry points for each of the reproduction paths, thereby efficiently utilizing the random access capability unique to disc media.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] Our invention relates to a readable and writable optical disc,and to a method for recording and a method for reproducing this opticaldisc. More particularly, our invention relates to an optical disc forrecording multimedia data including moving picture data, still imagedata, and audio data, and to a method for recording and a method forreproducing this optical disc.

[0003] 2. Description of the Related Art

[0004] Rewritable optical discs have for years had a maximum storagecapacity of approximately 650 MB, but this has been changed by thedevelopment of phase change type DVD-RAM discs with a capacity ofseveral gigabytes. Combined with the adoption of MPEG, and particularlyMPEG-2, standards for encoding digital AV data, DVD-RAM is widelyanticipated as a recording and reproducing medium with application inthe AV industry as well as the computer industry. More specifically,DVD-RAM media are expected to replace magnetic tape as the storagemedium of choice for AV recordings.

[0005] A. DVD-RAM

[0006] Increases in the storage density of rewritable optical disc mediaover the last few years has made it possible to use such media forapplications ranging from storing computer data and recording audio datato recording image data, including movies.

[0007] The signal recording surface of a conventional optical disc istypically formatted with lands and grooves, one of which is used as aguide groove for signal recording and reproducing. The data signal isthen recorded using only the land or the groove. With the advent of theland and groove recording method, however, it became possible to recordsignals to both the land and groove. This development approximatelydoubled the storage capacity of the disc (see Japanese Unexamined PatentApplication (kokai) 8-7282).

[0008] Further development of a zone CLV (constant linear velocity)method simplified and made it easy to implement a CLV recording andreproducing technique, an effective means of further increasing therecording density. (See Japanese Unexamined Patent Application (kokai)7-93873).

[0009] A major topic left for future development is how to use suchpotentially high capacity optical disc media to record AV datacontaining image data to achieve new functions and performance farsurpassing conventional AV products.

[0010] With the introduction of high capacity rewritable optical discmedia, optical discs are widely expected to replace conventional tapemedia for recording and reproducing AV content. The transition from tapeto disc recording media is also expected to greatly affect both theperformance and functions of AV recording and reproducing products.

[0011] One of the greatest benefits of a transition to disc is asignificant improvement in random access performance. While randomaccess to tape content is possible, it generally takes on the order ofminutes to rewind a full tape. This is several orders slower than thetypical seek time of optical disc media, which is on the order of atmost several ten milliseconds. Tape is therefore considered, forpractical purposes, not to be a random access medium.

[0012] The random access capability of optical disc media has also madepossible distributed, that is, noncontiguous, recording of AV data,which is not possible with conventional tape.

[0013]FIG. 38 is a block diagram of the drive device of a DVD recorder.As shown in FIG. 38, this DVD recorder comprises an optical pickup 11for reading data from the disc 10, an ECC (error correction code)processor 12, track buffer 13, switch 14 for changing track bufferinput/output, encoder 15, and decoder 16. An enlarged view of the disc17 format is also shown.

[0014] As indicated by the disc 17 format, the smallest unit used forrecording data to a DVD-RAM disc is the sector, which is 2 KB. Sixteensectors are combined as one ECC block, to which the ECC processor 12applies error correction coding.

[0015] The track buffer 13 is used for recording AV data at a variablebit rate in order to record AV data to a DVD-RAM disc more efficiently.While the read/write rate (Va) to a DVD-RAM disc is fixed, the bit rate(Vb) of the AV data is variable, based on the complexity of the AV datacontent (e.g., images if the AV data is video). The track buffer 13 isused to absorb this bit rate difference. This means that the trackbuffer 13 is unnecessary if the AV data bit rate is also fixed, as it isin the Video CD format.

[0016] This track buffer 13 can be even more effectively used bydispersed placement of the AV data on the disc. This is explained withreference to FIG. 39.

[0017]FIG. 39(a) shows the disc address space. If the AV data isrecorded divided between contiguous area A1 between addresses a1 and a2,and contiguous area A2 between a3 and a4 as shown in FIG. 39(a), the AVdata can be continuously reproduced by supplying data accumulated in thetrack buffer 13 to the decoder while the optical head seeks from a2 toa3. This is shown in FIG. 39(b).

[0018] Once reading AV data starts from al at time t1, it is both inputto the track buffer 13 and output from the track buffer 13 with dataaccumulating in the track buffer at the rate (Va−Vb), that is, thedifference between the input rate Va to the track buffer and the outputrate Vb from the track buffer. This continues to address a2 at time t2.Assuming that the data volume accumulated to the track buffer at thistime is B(t2), data supply to the decoder can continue until the dataB(t2) accumulated to the track buffer is depleted at time t3 at whichreading resumes from address a3.

[0019] In other words, if it is assured that a certain volume of data([a1, a2]) is read before a seek operation is performed, AV data can becontinuously supplied to the decoder while the seek is in progress.

[0020] It should be noted that this example considers reading, that is,reproducing, data from DVD-RAM, but the same concept applies for writingor recording data to DVD-RAM.

[0021] It will thus be obvious that insofar as a specified amount ofdata is recorded continuously to DVD-RAM disc, continuous reproductionand recording is possible even if the AV data is noncontiguouslyrecorded to the disc.

[0022] B. MPEG

[0023] A common AV data format is described next below.

[0024] As noted above, AV data is recorded to DVD-RAM media using theMPEG international standard, also known as IS0/IEC 13818.

[0025] Even though DVD-RAM discs have a large, plural gigabyte,capacity, this is still not sufficient for recording uncompresseddigital AV data. A way to compress and record AV data is thereforenecessary. MPEG (IS0/IEC 13818) is now widely used around the world forAV data compression. MPEG decoders (compression/decompression ICs) havealso been realized with advances in IC devices. This has enabled the DVDrecorder to handle MPEG compression and decompression internally.

[0026] MPEG signal processing is able to achieve high efficiency datacompression chiefly as a result of the following two features.

[0027] First is that compression using a time correlation characteristicbetween frames (known as pictures in MPEG) is used in conjunction withconventional compression using a spatial frequency characteristic formoving picture data compression. Each video sequence of an MPEG videosignal stream is divided into one or more groups of pictures, each groupof pictures comprising one or more pictures of three different types:I-pictures (intraframe coded pictures), P-pictures (predictive-codedpictures, that is, intracoded with reference to a preceding picture),and B-pictures (bidirectionally predictive-coded pictures, that is,intraframe coded with reference to preceding and following pictures).

[0028]FIG. 40 shows the relationship between I, P, and B pictures. Asshown in FIG. 40, P-pictures refer to temporally preceding I- orP-pictures in the sequence, while B-pictures refer to the firstpreceding and following I- or P-pictures. It should also be noted thatbecause B-pictures reference an upcoming I- or P-picture, the displayorder of the pictures may not match the coding order of the pictures inthe compressed data bitstream.

[0029] The second feature of MPEG coding is that code size isdynamically allocated by picture unit according to the complexity of theimage. An MPEG decoder has an input buffer, and by accumulating data inthis decoder buffer a large amount of code can be allocated to compleximages that are difficult to compress.

[0030] Three types of audio coding are used for the audio portion of aDVDRAM recording: MPEG audio with data compression, Dolby Digital^((R))(also known as AC-3), and noncompressive linear pulse code modulation(LPCM). Both Dolby Digital^((R)) and LPCM are fixed bit rate codingmethods, but MPEG audio coding can select from several compression rateson an audio frame basis, although audio compression is not as high asvideo stream compression.

[0031] The resulting compressed video and audio streams are multiplexedto a single stream using a method known as the MPEG system. FIG. 41shows the organization of an MPEG system stream. As shown in FIG. 41,each 2 KB sector comprises a pack header 41, packet header 42, andpayload 43. The MPEG system thus has a hierarchical structure comprisingpacks and packets. Each packet comprises a packet header 42 and payload43. AV data is segmented from the beginning into blocks of anappropriate size for storage to the payload 43.

[0032] Referring to the AV data stored in the associated payload 43, thepacket header 42 contains a stream ID for identifying the data stored inthe associated packet, and a decoding time stamp (DTS) and presentationtime stamp (PTS) identifying the decoding time and presentation time ofthe data contained in the payload in 90 kHz precision. If the decodingand presentation are simultaneous, as in the case of audio data, the DTScan be omitted.

[0033] A pack is a unit of plural packets. In DVD-RAM, however, there isone pack for each packet, and each pack therefore comprises a packheader 41 and packet (containing a packet header 42 and payload 43).

[0034] The pack header contains a system clock reference (SCR)expressing with 27 MHz precision the time at which the data contained inthis pack is input to the decoder buffer.

[0035] An MPEG system stream thus comprised is recorded one pack to asector (=2048 bytes) on DVD-RAM.

[0036] A decoder for decoding the above-noted MPEG system stream isdescribed next below. FIG. 42 is a block diagram of an exemplary decodermodel (P_STD) of an MPEG system stream decoder. Shown in FIG. 42 are thesystem time clock (STC) 51, that is, the internal reference clock fordecoder operation; a demultiplexer 52 for decoding (demultiplexing) thesystem stream; video decoder input buffer (video buffer) 53; videodecoder 54; re-ordering buffer 55 for temporarily storing I and Ppictures for absorbing the difference in the coding (data) sequence andpresentation sequence that occurs between B pictures and I and Ppictures; a switch 56 for adjusting the output order of the I, P, and Bpictures buffered to the re-ordering buffer 55; an audio decoder 58; andaudio decoder input buffer (audio buffer) 57.

[0037] This MPEG system decoder processes the above-noted MPEG systemstream as follows.

[0038] When the time indicated by the STC 51 and the SCR written to thepack header match, the pack is input to the demultiplexer 52. Thedemultiplexer 52 then interprets the stream ID in the packet header, andpasses the audio stream and video stream contained in the payload datato the appropriate decoder buffers. The PTS and DTS are also read fromthe packet header.

[0039] When the times indicated by the STC 51 and DTS match, the videodecoder 54 reads and decodes the picture data from the video buffer 53.I and P pictures are stored to the re-ordering buffer 55 while Bpictures are presented directly to screen. If the picture being decodedby the video decoder 54 is an I or P picture, the switch 56 switches tothe re-ordering buffer 55 to output the previous I or P picture from there-ordering buffer 55; if a B picture is decoded, the switch 56 switchesto the video decoder 54.

[0040] Similarly to the video decoder 54, the audio decoder 58 reads anddecodes one audio frame of data from the audio buffer 57 when the PTSmatches the STC 51 (a DTS is not recorded for audio data).

[0041] An exemplary method of multiplexing an MPEG system stream isdescribed next with reference to FIG. 43. Note that a sequence of videoframes is shown in FIG. 43(a), the change in data storage to the videobuffer is shown in FIG. 43(b), a typical MPEG system stream is shown inFIG. 43(c), and an audio signal is shown in FIG. 43(d). Each of FIGS.43(a) to (d) are shown on a common time base (horizontal axis). Thevertical axis in FIG. 43(b) indicates the amount of data stored to thevideo buffer. The bold line in this graph thus indicates the change overtime in the buffered video data volume. The slope of this line isindicative of the video bit rate, and shows that data is input to thevideo buffer at a constant rate. The decrease in buffered data atregular intervals indicates the progression of data decoding. Theintersection of the dotted line extension of the graphed line with thetime base (horizontal axis) indicates the time at which video frametransfer to the video buffer begins.

[0042] MPEG encoding is described next using by way of example coding acomplex image A in the video data stream. As shown in FIG. 43(b), imageA requires a large coding block, and data transfer to the video buffermust therefore begin from a time t1 before the image A decoding time.Note that the time from data input start time t1 to decoding is referredto as vbv_delay below. AV data is thus multiplexed to the position(time) of the shaded video pack.

[0043] Unlike video data, audio data does not require dynamic codingsize control. It is therefore not necessary for audio data transfer tostart before decoding starts, and audio data is thus typicallymultiplexed only slightly before decoding starts. Video data is thusmultiplexed to the MPEG system stream before the audio data.

[0044] It should be further noted that data can be accumulated to thebuffer for a limited time in the MPEG system. More specifically, theMPEG system standard requires all data other than still image data beoutput to the decoder from the buffer within one second of being storedto the buffer. This means that there is at most a one second offsetbetween video data and audio data multiplexing (or more precisely, thetime required for video frame reordering).

[0045] It will also be obvious that while the MPEG system stream isdescribed above with video data preceding the audio, the audio cantheoretically precede the video. This type of stream can be purposelygenerated by using for the video data simple images to which a highcompression rate can be applied, and transferring the audio data earlierthan required. Even in this case, however, the audio can precede thevideo by at most one second due to the restrictions imposed by the MPEGstandard.

[0046] Video CD

[0047] Video CD, a moving picture format incorporating an entry pointconcept for playback control, is described next.

[0048] The Video CD standard was published in 1993. Version 2.0 of thestandard, incorporating a playback control feature, was released thefollowing year in 1994. Video CD can store a maximum 74 minutes of videocompressed using the MPEG-1 standard, together with a maximum 2000 highresolution still images (704×480 dots). A simple menu is compiled by theplayback control function so that the presented content can becontrolled to display only a required segment or so that a user canselect specific content for display.

[0049] The Video CD format allows recording absolute addresses on thedisc as “entry points.” An entry point is a specific address where theplayback path can be entered to begin playback. Entry points can beachieved by using address information and time information. By usingentry points, it is possible for playback to jump to a specificallyrecorded absolute address when playback reaches an entry point in theplayback path, and the disc player can thus be controlled to jump frompoint to point in the disc content.

[0050] The Video CD format, however, requires a 1:1 correlation betweenentry points and the bitstream, and cannot use independent entry pointsto a plurality of reproduction paths.

[0051] In addition, Video CD is a non-writable medium, which means thatthe user cannot add or delete entry points to the content. The usertherefore cannot create a reproduction path or entry points with logicalmeaning, and cannot make effective use of the disc's randomaccessibility.

[0052] Digital video

[0053] Digital video tape, and particularly the Digital Video CassetteTape Recorder (DVC) medium that has become most popular, is describednext.

[0054] Published in 1994, the DVC standard records and reproduces at 19Mb/s to 30 Mb/s using discrete cosine transform (DCT) and variablelength coding (VLC) for image compression and signal processing.

[0055] The subcode data recorded with the video data can include in theDVC format the track number (Title Time Code) indicative of therecording time from the first recorded frame at the beginning of thetape, a time code (Rec Date) indicating the date the recording was made,and a time code (Rec Time) indicating the time the recording was made.This makes it possible to detect interruptions in the time code and usethese interruptions as entry points to the content.

[0056] The drawback to this scheme is that because managementinformation such as used by a computer is not present, it is notpossible to freely set a desired time as an entry point from whichplayback is possible.

[0057] Another obvious drawback to DVC is it is a tape-based medium.Random access performance is thus poor, and plural reproduction pathscannot be achieved.

[0058] To use plural reproduction paths or selectable entry points withDVC type media, the reproduction device must have memory to store thisdata, and the data cannot be used on different reproduction devices.

[0059] The introduction of DVD-RAM media solves the problem of randomaccess performance present in DVC media, and makes it possible toachieve a new consumer AV product whereby entry points to pluralreproduction paths on a Video CD can be freely used.

[0060] Problem to be Solved

[0061] The object of the present invention is to provide a DVD recorderthat solves following problems hindering obtaining maximum performancefrom DVD-RAM media, a high capacity rewritable storage medium widelyanticipated as the next generation in AV recording media.

[0062] That is, the greatest problem in recording entry points to aplurality of reproduction paths and using these entry points forreproduction on a DVD recorder is how to best utilize the unique randomaccessibility of the disc medium to set individual entry points asdesired to any of a plurality of reproduction paths, thus achievingfunctionality that is not possible with tape media.

SUMMARY OF THE INVENTION

[0063] To resolve the above problem, in an optical disc for recording aprogram stream of audio-visual content and management information formanaging the program stream, the management information preferablycomprises according to the present invention: information (C_V_S_PTM)for specifying a start time of the program stream; information(C_V_E_PTM) for specifying an end time of the program stream; and entrypoint information (M_C_EPI/S_C_EPI) for accessing the program stream ata desired point, and reproducing the program stream from the desiredpoint.

[0064] It is therefore not necessary with an optical disc according tothe present invention for entry point information to be incorporatedinto the program stream itself.

[0065] When the program stream is moving picture content, the entrypoint information is preferably time information (EP_PTM).

[0066] Using time information makes it possible to determine thedistance (time) from the beginning of the reproduction path.

[0067] When the program stream is still image content, the entry pointinformation is preferably still image number information (S_VOB_ENTN).

[0068] This still image number information represents the number of thestill image in the bitstream, and therefore makes it possible todetermine how far from the beginning of the reproduction path.

[0069] Yet further preferably, the entry point information also includestext information (PRM_TXTI).

[0070] By also including text information, the content of a desiredaccess point can be displayed.

[0071] In a further optical disc for recording a program stream ofaudio-visual content, and management information for managing theprogram stream, the management information contains according to thepresent invention: information (C_V_S_PTM) for specifying a first starttime of the program stream; information (C_V_E_PTM) for specifying afirst end time of the program stream; and first entry point information(M_C_EPI/S_C_EPI) for accessing the program stream at a desired pointand reproducing the program stream from the desired point whenreproducing the program stream from the first start time to the firstend time; information (C_V_S_PTM) for specifying a second start time ofthe program stream; information (C_V_E_PTM) for specifying a second endtime of the program stream; and second entry point information(M_C_EPI/S_C_EPI) for accessing the program stream at a desired pointand reproducing the program stream from the desired point whenreproducing the program stream from the second start time to the secondend time.

[0072] There are cases when the program stream segment defined as afirst reproduction path from the first start time to the first end time,and the program stream segment defined as a second reproduction pathfrom the second start time to the second end time, overlap. However,even if these first and second reproduction paths overlap, entry pointinformation can be individually and separately set for both paths. Entrypoints set for the first reproduction path therefore do not work on thesecond reproduction path.

[0073] The present invention further relates to an optical disc playerfor reproducing an optical disc according to the present invention asdescribed above. The optical disc player comprises: a storage means(7802) for reading and storing entry point information from the opticaldisc; a decoder (7806) for decoding the program stream and generatingaddress information during program stream reproduction; a conversionmeans (7802) for converting the address information to point informationin the program stream;Å@a selection means (7802) for selecting entrypoint information closest to the point information; a conversion means(7802) for converting the selected entry point information to addressinformation; and a drive means (7808) for jumping to a location based onthe converted address information. The decoder decodes and reproducesfrom the jump destination.

[0074] In the optical disc player, the point information is preferablytime information (EP_PTM) when the program stream is moving picturecontent.

[0075] Further preferably, when the program stream is still imagecontent the point information is still image number information(S_VOB_ENTN).

[0076] Yet further preferably, the entry point information furtherincludes text information (PRM_TXTI), and the decoder further reproducesthe text information.

[0077] Our invention can be further expressed as a playback method forplaying back an optical disc where the optical disc is an optical discaccording to the present invention as described above. This playbackmethod has steps for: reading and storing entry point information fromthe optical disc; decoding the program stream and generating addressinformation during program stream reproduction; converting the addressinformation to point information in the program stream;Å@selecting entrypoint information closest to the point information; converting theselected entry point information to address information; jumping to alocation based on the converted address information, and decoding andreproducing from the jump destination.

[0078] The present invention also provides an optical disc recorder forrecording to an optical disc according to the present invention asdescribed above. The optical disc recorder comprises: an interface(7801) for receiving entry point information input; means (7804, 7806)for generating address information at the time the entry pointinformation is received; a conversion means (7802) for converting theaddress information to entry point information in the program stream; astorage means (7802) for temporarily storing the entry pointinformation; and a drive means (7808) for recording the stored entrypoint information to the optical disc.

[0079] As noted above, when the program stream is moving picturecontent, the point information of this optical disc recorder ispreferably time information (EP_PTM).

[0080] Yet further preferably, the point information is still imagenumber information (S_VOB_ENTN) when the program stream is still imagecontent.

[0081] Yet further preferably, the entry point information furtherincludes text information (PRM_TXTI), and the storage means generatesand stores said text information.

[0082] The invention also provides a recording method for an opticaldisc according to the present invention as described above. Thisrecording method has steps for receiving entry point information input;generating address information at the time the entry point informationis received; converting the address information to entry pointinformation in the program stream; temporarily storing the entry pointinformation; and recording the stored entry point information to theoptical disc.

BRIEF DESCRIPTION OF THE DRAWINGS

[0083] These and other objects and features of the present inventionwill be readily understood from the following detailed description takenin conjunction with preferred embodiments thereof with reference to theaccompanying drawings, in which like parts are designated by likereference numerals and in which:

[0084]FIG. 1 shows the logical structure of a disc according to apreferred embodiment of the present invention;

[0085]FIG. 2 shows the internal structure of an AV file for movies;

[0086]FIG. 3 shows the internal structure of an AV file for stillimages;

[0087]FIG. 4 shows the relationship between AV data and managementinformation;

[0088]FIG. 5 shows the structure of the RTR_VMG block;

[0089]FIG. 6 shows the structure of the RTR_VMGI block;

[0090]FIG. 7 shows the structure of the VERN and TM_ZONE format;

[0091]FIG. 8 shows the structure of the PL_SRP block;

[0092]FIG. 9 shows the structure of the PL_TY and PL_CREATE format;

[0093]FIG. 10 shows the structure of the PTM recording format;

[0094]FIG. 11 shows the structure of the S_VOB_ENTN recording format;

[0095]FIG. 12 shows the structure of the M_AVFIT block;

[0096]FIG. 13 shows the structure of the V_ATR and A_ATR format;

[0097]FIG. 14 shows the structure of the movie SP_PLT for mat;

[0098]FIG. 15 shows the structure of the M_AVFI block;

[0099]FIG. 16 shows the structure of the M_VOBI block;

[0100]FIG. 17 shows the structure of the VOB_TY format;

[0101]FIG. 18 shows the structure of the TMAPI block;

[0102]FIG. 19 shows the structure of the VOBU_ENT format;

[0103]FIG. 20 shows the structure of the S_AVFIT block;

[0104]FIG. 21 shows the structure of the S_AA_STI and S_AAFI block;

[0105]FIG. 22 shows the structure of the V_ATR and OA_ATR format;

[0106]FIG. 23 shows the structure of the still image SP_PLT format;

[0107]FIG. 24 shows the structure of the S_AVFI block;

[0108]FIG. 25 shows the structure of the S_VOB_ENT block;

[0109]FIG. 26 shows the structure of the S_VOB_ENT_TY format;

[0110]FIG. 27 shows the structure of the S_AAFI_GI and S_AAGI_SRP block;

[0111]FIG. 28 shows the structure of the S_AAGI block;

[0112]FIG. 29 shows the structure of the AA_TY format;

[0113]FIG. 30 shows the structure of the UD_PGCIT block;

[0114]FIG. 31 shows the structure of the TXTDT_MG block;

[0115]FIG. 32 shows the structure of the PGCI block;

[0116]FIG. 33 shows the structure of the PG_TY format;

[0117]FIG. 34 shows the structure of the CI block;

[0118]FIG. 35 shows the structure of the C_TY format;

[0119]FIG. 36 shows the structure of the C_EPI block;

[0120]FIG. 37 shows the structure of the EP_TY1 format;

[0121]FIG. 38 is a block diagram of a DVD recorder drive;

[0122]FIG. 39(a) shows the volume address space of a disc, and (b) showsthe change in data accumulation in the track buffer;

[0123]FIG. 40 shows the correlation between picture types in an MPEGvideo system stream;

[0124]FIG. 41 shows the structure of an MPEG system stream;

[0125]FIG. 42 is a block diagram of an MPEG system decoder (P_STD);

[0126]FIG. 43(a) shows video data, (b) shows the change in dataaccumulation in the video buffer, (c) shows the MPEG system stream, and(d) show the audio data;

[0127]FIG. 44 shows the correlation between AV data and entry points;

[0128]FIG. 45 shows the correlation between a program chain PGC andentry points;

[0129]FIG. 46 is a block diagram of a DVD recorder according to thepresent invention;

[0130]FIG. 47 is used to describe movie cell entry point reproduction inthe DVD recorder shown in FIG. 46;

[0131]FIG. 48 is used to describe still image cell entry pointreproduction in the DVD recorder shown in FIG. 46;

[0132]FIG. 49 is a flow chart of entry point reproduction;

[0133]FIG. 50 is used to describe entry point reproduction in areproduction path containing a still image;

[0134]FIG. 51 is used to describe a high speed search in the DVDrecorder shown in FIG. 46;

[0135]FIG. 52 is a flow chart of the high speed search operationdescribed in FIG. 51;

[0136]FIG. 53 is a flow chart of an entry point recording operationaccording to the present invention;

[0137]FIG. 54 is an exemplary display of entry points to a bitstream ina DVD recorder shown in FIG. 46; and

[0138]FIG. 55 is an exemplary display of entry point types to abitstream in a DVD recorder shown in FIG. 46.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0139] A DVD recorder and DVD-RAM disc are described below as apreferred embodiment of the present invention with reference to theaccompanying figures.

[0140] Logical Structure of DVD-RAM

[0141] The logical structure of a DVD-RAM disc is described first belowwith reference to FIG. 1. FIG. 1 shows the physical sector address areaof the disc, and the structure whereby data is recorded to the disc aspart of a file system.

[0142] The physical sector address area of the disc starts with alead-in area to which a reference signal for servo stabilization, and anID signal for differentiating DVD-RAM media from other media, arerecorded. The user data area follows the lead-in area. Logically validdata is recorded to the user data area. A lead-out area ends thephysical sector address area; a reference signal is also recorded here.

[0143] File system management information, called volume information, isrecorded at the beginning of the user data area. The file system is notdirectly related to the present invention, and description thereof isthus omitted below. It should be noted, however, that by using a filesystem, data recorded to the disc can be managed as files and adirectory to the files as shown in FIG. 1.

[0144] All data handled by the DVD recorder is filed under the DVD_RTAVdirectory directly below the root directory as shown in FIG. 1.

[0145] Files handled by a DVD recorder can be grouped into three broadcategories: a management information file and one or more AV files, anda copy of the management information file.

[0146] AV files can be an RTR_MOVIE.VRO file recording moving picturecontent (referred to as video below), an RTR_STILL.VRO file recordingstill image data or still image data and simultaneously recorded audiodata, or a VR_AUDIO.VRO file recording audio data only.

[0147]FIG. 2 shows the file structure of an RTR_MOVIE.VRO file recordingvideo content. As shown in FIG. 2, MPEG program streams (M_VOB (MovieVideo Object)) are arranged in recording sequence in the RTR_MOVIE.VROfile.

[0148] Each program stream (M_VOB) is built from a plurality of VideoObject Units (VOBU), each with a video reproduction time of 0.4 sec. to1.0 sec.

[0149] Each VOBU comprises a number of video packs (V_PCK), audio packs(A_PCK), and subpicture packs (SP_PCK); each pack is 2 KB. Notice thataudio packs are multiplexed with the video in an M_VOB.

[0150] The video data in each VOBU further comprises one or more Groupof Pictures (GOP). The GOP is the decoding unit for MPEG video, startswith an I-picture, and contains plural P- or B-pictures.

[0151]FIG. 3 shows the structure of an RTR_STILL.VRO file for recordingstill images and audio data. As shown in FIG. 3, an RTR_STILL.VRO filecontains S_VOB (Still Picture Video Objects), the MPEG program streamfor still images, arranged in recording sequence.

[0152] The greatest difference between an S_VOB and M_VOB is that anS_VOB records still image data instead of moving picture data, and thestill image data (video part) is followed by the audio data (audio part)instead of multiplexing the video and audio.

[0153] An S_VOB also contains one VOBU, which comprises a V_PCK, A_PCK,and SP_PCK.

[0154] An VR_AUDIO.VRO contains only the audio part of an MPEG programstream.

[0155] AV Data and Management Information

[0156] The relationship between M_VOB, S_VOB, and management informationis described next below with reference to FIG. 4.

[0157] As described above, there are two types of AV data, M_VOB andS_VOB. Management information M_VOBI for each M_VOB is stored for eachM_VOB where the M_VOBI records attributes of the corresponding M_VOB.Individually managing S_VOBs, however, would greatly increase the amountof management information. Management information S_VOGI is thereforeused to manage a group S_VOG containing plural S_VOB units. This S_VOGIrecords attributes for the corresponding S_VOB group.

[0158] What is important to note here is that MPEG stream data does nothave a linear correlation between time and data size. As noted above,the MPEG system stream is compressed using temporal correlationcharacteristics and variable length coding techniques (includingvariable bit rate coding) in order to achieve high compressionefficiency. As a result there is not necessarily a direct correlationbetween (reproduction) time and data size (address).

[0159] Therefore, an M_VOBI also contains a filter (TMAP) for convertingtime and address information, and an S_VOGI also contains a filter(S_VOB Entries) for converting a still image number in an S_VOG groupand address.

[0160] Management information for the reproduction path is describednext below.

[0161] The reproduction path is defined as a program chain (PGC) orsequence of cells describing all or part of a range of M_VOB or S_VOGblocks.

[0162] The reproduction path can be either of two types: an original PGCreferring to all AV data on the disc, or a user-defined PGC defining auser-selected reproduction sequence of AV data on the disc.

[0163] The original PGC is also called a Program Set having a Programlayer logically bundling a plurality of cells.

[0164] A user-defined PGC is also called a Play List. Unlike an originalPGC, a Play List does not have a Program layer.

[0165] Management Information File

[0166] The content of the management information file RTR.IFO, alsoshown as VR_MANGR. IFO, is described next below with reference to FIG. 5to FIG. 55.

[0167] RTR_VMG (FIG. 5)

[0168] The VR_MANGR.IFO file contains real-time recording videomanagement information RTR_VMG. RTR_VMG comprises seven tables:RTR_VMGI, M_AVFIT, S_AVFIT, ORG_PGCI, UD_PGCIT, TXTDT_MG, and MNFIT.

[0169] These seven tables are described in detail next below.

[0170] RTR_VMGI (FIG. 6)

[0171] Real-time recording video management information RTR_VMGIincludes video management information table VMGI_MAT and play listsearch pointer table PL_SRPT.

[0172] VMGI_MAT (FIG. 6)

[0173] The video management information management table VMGI_MAT storesthe following information relating to the entire disc. The reproducingdevice and recording device, referred to as simply disc player andrecorder, respectively, below, first read this VMGI_MAT to detect theoverall structure of the disc.

[0174] VMG_ID (video management identifier)

[0175] Stores the identifier DVD_RTAV_VMG0 identifying the disc asstoring video recording data.

[0176] RTR_VMG EA (RTR_VMG end address)

[0177] Stores the RTR_VMG end address.

[0178] VMGI_EA (VMGI end address)

[0179] Stores the VMGI end address.

[0180] VERN (version number)

[0181] Records the version number of the recording format of the storedvideo recording data according to the format shown in FIG. 7.

[0182] TM_ZONE (time zone)

[0183] Records the time zone used for all time information recorded tothe disc. As shown in FIG. 7, the TM_ZONE stores a time zone stamp TZ_TYindicating whether time information is based on Greenwich Mean Time or aregional time standard (such as Eastern Standard Time (EST) or JapanStandard Time (JST)), and a time zone offset TZ_OFFSET recording thetime difference to Greenwich Mean Time.

[0184] STILL_TM (still time)

[0185] Stores the still time used for presenting still images withoutsound.

[0186] CHRS (character set code for primary text display)

[0187] Defines the character set code to use for primary text displaysdescribed below.

[0188] RSM_MRKI (resume marker management information)

[0189] Stores the time code of the video at which playback last stopped.

[0190] DISC_REP_PICTI (disc representative picture information)

[0191] Stores the time code of the still image selected asrepresentative of the disc.

[0192] DISC_REP NM (disc representative name)

[0193] Stores the character string representing the disc.

[0194] M_AVFIT SA (M AVFIT start address)

[0195] Stores the start address of the movie AV file information tableM_AVFIT. This start address is used in the seek operation for accessingthe M_AVFIT table.

[0196] S_AVFIT SA (S_AVFIT start address)

[0197] Stores the start address of the still image AV file informationtable S_AVFIT. This start address is used in the seek operation foraccessing the S_AVFIT table.

[0198] ORG_PGCI_SA (ORG_PGCI start address)

[0199] Stores the start address of the original PGC information. Thisstart address is used in the seek operation for accessing the originalPGC.

[0200] UD_PGCIT_SA (UD_PGCIT start address)

[0201] Stores the start address of the user-defined PGC informationtable. This start address is used in the seek operation for accessingthe user-defined PGC information table.

[0202] TXTDT_MG_SA (TXTDT_MG start address)

[0203] Stores the start address of the text data management informationTXTDT_MG. This start address is used in the seek operation for accessingthe text data management information TXTDT_MG.

[0204] MNFIT_SA (MNFIT start address)

[0205] Stores the start address of the management file information tableMNFIT. This address is used in the seek operation for accessing theMNFIT table.

[0206] PL_SRPT (play list search pointer table) (FIG. 8)

[0207] The play list search pointer table PL_SRPT records play listsearch pointer table information PL_SRPTI and n play list searchpointers PL_SRP.

[0208] PL_SRPTI (play list search pointer table information) (FIG. 8)

[0209] The play list search pointer table information PL_SRPTI recordsthe following information for accessing a play list search pointerPL_SRP.

[0210] PL_SRP_Ns (number of play list search pointers)

[0211] Stores the number of play list search pointers PL_SRP.

[0212] PL_SRPT_EA (PL_SRPT end address)

[0213] Stores the end address of this play list search pointer tablePL_SRPT.

[0214] PL_SRP (play list search pointer) (FIG. 8)

[0215] Records the following information for accessing the actual playlist data, that is, the user-defined PGC.

[0216] PL_TY (play list type)

[0217] Stores one of the following values for identifying the play listtype using the format shown in FIG. 9.

[0218] 0000b: video only

[0219] 0001b: still images only

[0220] 0010b: both video and still images

[0221] PGCN (PGC number)

[0222] Stores the PGC number for the associated play list. The PGCnumber is the recording sequence of PGC information in the UD_PGCITdescribed below.

[0223] PL_CREATE_TM (play list creation date/time)

[0224] Stores the date and time the play list was created according tothe format shown in FIG. 9.

[0225] PRM_TXTI (play list text information)

[0226] Stores text information indicative of play list content. Forexample, if the play list is a television program, PRM_TXTI could recordthe name of the show. PRM_TXTI includes an ASCII code field, and a fieldfor the character code set defined by the above-noted CHRS.

[0227] IT_TXT_SRPN (IT_TXT_SRP number)

[0228] If the optional IT_TXT containing the play list content isrecorded in addition to the above-noted primary text, the IT_TXT_SRPnumber is stored as a link to the IT_TXT recorded in TXTDT_MG. ThisIT_TXT_SRP number is the recording sequence in TXTDT_MG, describedbelow.

[0229] THM_PTRI (thumbnail pointer information)

[0230] Stores thumbnail image information for the play list.

[0231] THM_PTRI (FIG. 8)

[0232] THM_PTRI stores the following information indicating a thumbnailimage location.

[0233] CN (cell number)

[0234] Stores the cell number containing the thumbnail image. The cellnumber is the recording sequence of the cell information in the UD_PGCIfor this play list.

[0235] THM_PT (thumbnail image pointer)

[0236] Stores the presentation time of the video frame used as thethumbnail image according to the PTM (presentation time) describingformat as shown in FIG. 10 if the cell indicated by CN is a video cell.PTM is written according to the reference time of the time stamp writtenin the MPEG program stream.

[0237] Stores the still image VOB entry number of the still image usedas the thumbnail image according to the S_VOB_ENTN describing format asshown in FIG. 11 if the cell indicated by CN is a still image cell.

[0238] M_AVFIT (FIG. 12)

[0239] The movie AV file information table M_AVFIT stores managementinformation for the movie AV file RTR_MOVIE.VRO, and comprises M_AVFITI,M_VOB_STI, and M_AVFI.

[0240] M_AVFITI (movie AV file information table information) (FIG. 12)

[0241] Stores the following information for accessing M_VOB_STI andM_AVFI.

[0242] M_AVFL_Ns (movie AV file information number)

[0243] Indicates the number of AVFI information fields following. If 0,no AVFI is present; if 1, an AVFI is present. AVFI presence correspondsto the presence of movie AV file RTR_MOVIE.VRO.

[0244] M_VOB_STI_Ns (M_VOB_STI number)

[0245] Indicates the number of following M_VOB_STI fields.

[0246] M_AVFIT_EA (M_AVFIT end address)

[0247] Stores the M_AVFIT end address.

[0248] M_VOB_STI (movie VOB stream information) (FIG. 12)

[0249] Stores the following as movie VOB stream information.

[0250] V_ATR (video attributes)

[0251] Stores the following video attributes according to the format asshown in FIG. 13.

[0252] Video compression mode

[0253] Stores one of the following values indicating the videocompression mode.

[0254] 00b: MPEG_(—)1

[0255] 01b: MPEG_(—)2

[0256] TV system

[0257] Stores one of the following values indicating the televisionsystem.

[0258] 00b: 525/60 (NTSC)

[0259] 01b: 625/50 (PAL)

[0260] Aspect ratio

[0261] Stores one of the following values indicating the aspect ratio.

[0262] 00b: 4×3

[0263] 01b: 16×9

[0264] line21_switch _(—)1

[0265] Stores one of the following values indicating whether closedcaption data for field 1 is contained in the video stream.

[0266] 1b: recorded

[0267] 0b: not recorded

[0268] line21_switch _(—)2

[0269] Stores one of the following values indicating whether closedcaption data for field 2 is contained in the video stream.

[0270] 1b: recorded

[0271] 0b: not recorded

[0272] Video resolution

[0273] Stores one of the following values indicating the videoresolution.

[0274] 000b: 720×480 (NTSC), 720×576 (PAL)

[0275] 001b: 702×480 (NTSC), 702×576 (PAL)

[0276] 010b: 352×480 (NTSC), 352×576 (PAL)

[0277] 011b: 352×240 (NTSC), 352×288 (PAL)

[0278] 100b: 544×480 (NTSC), 544×576 (PAL)

[0279] 101b: 480×480 (NTSC), 480×576 (PAL)

[0280] AST_Ns (audio stream number)

[0281] Stores the number of audio streams recorded to the correspondingVOB.

[0282] SPST_Ns (still picture stream number)

[0283] Stores the number of still picture streams recorded to thecorresponding VOB.

[0284] A_ATR0 (audio stream 0 attributes)

[0285] Stores the following attributes for the audio recorded to audiostream 0 using the format as shown in FIG. 13.

[0286] Audio coding mode

[0287] Stores one of the following values indicating the audiocompression method.

[0288] 000b: Dolby AC-3

[0289] 001b: MPEG audio without an extension stream

[0290] 010b: MPEG audio with an extension stream

[0291] 011b: linear PCM

[0292] Application Flag

[0293] Stores one of the following values indicating the audioapplication.

[0294] 00b: not applicable

[0295] 01b: mixed number of audio channels

[0296] 10b: enhancement channel included

[0297] Quantization/DRC

[0298] Stores one of the following values for identifying whetherdynamic range control (DRC) information is present.

[0299] 00b: DRC not contained in MPEG stream

[0300] 01b: DRC contained in MPEG stream

[0301] If LPCM is used, the following value is stored to identify thequantization level.

[0302] 00b: 16 bit

[0303] fs

[0304] The following value is stored to identify the sampling frequency.

[0305] 00b: 48 kHz

[0306] Number of Audio channels

[0307] Stores one of the following values indicating the number of audiochannels.

[0308] 0000b: 1 channel (monaural)

[0309] 0001b: 2 channel (stereo)

[0310] 0010b: 3 channel

[0311] 0011b: 4 channel

[0312] 0100b: 5 channel

[0313] 0101b: 6 channel

[0314] 0110b: 7 channel

[0315] 0111b: 8 channel

[0316] 1001b: 2 channel (dual monaural)

[0317] Bitrate

[0318] Stores one of the following values indicating the bitrate.

[0319] 0000 0001b: 64 kbps

[0320] 0000 0010b: 89 kbps

[0321] 0000 0011b: 96 kbps

[0322] 0000 0100b: 112 kbps

[0323] 0000 0101b: 128 kbps

[0324] 0000 0110b: 160 kbps

[0325] 0000 0111b: 192 kbps

[0326] 0000 1000b: 224 kbps

[0327] 0000 1001b: 256 kbps

[0328] 0000 1010b: 320 kbps

[0329] 0000 1011b: 384 kbps

[0330] 0000 1100b: 448 kbps

[0331] 0000 1101b: 768 kbps

[0332] 0000 1110b: 1536 kbps

[0333] What is important here is that if the corresponding audio streamis an MPEG audio stream with an extension stream, only the bitrate ofthe base channel, not including the extension stream, is recorded. Thisis because compression using a VLC technique is used for the extensionstream, and the extension stream therefore cannot be defined using afixed bitrate as above.

[0334] A_ATR1 (audio stream 1 attributes)

[0335] Stores the following attributes of audio stream 1 using theformat as shown in FIG. 13. Note that these attributes are defined usingthe same fields used with A_ATR0 and described above, and furtherdescription is thus omitted here.

[0336] SP_PLT (subpicture color palette)

[0337] Records the subpicture color palette information using the formatshown in FIG. 14.

[0338] M_AVFI (FIG. 15)

[0339] The movie AV file information M_AVFI comprises the followinginformation for accessing a movie VOB: M_AVFI_GI, M_VOBI_SRP, andM_VOBI.

[0340] M_AVFI_GI (movie AV file general information) (FIG. 15)

[0341] Stores the movie VOB information search pointer countM_VOBI_SRP_Ns.

[0342] M_VOBI_SRP_Ns (movie VOB information search pointer number)

[0343] Records the number of movie VOB information search pointersM_VOBI_SRP.

[0344] M_VOBI_SRP (movie VOB information search pointer) (FIG. 15)

[0345] Stores address information for accessing each M_VOBI.

[0346] M_VOBI SA (movie VOB information start address)

[0347] Stores the M_VOBI start address used for a seek operationaccessing the corresponding VOBI information.

[0348] M_VOBI (movie VOB information) (FIG. 16)

[0349] Stores the following movie VOB management information: M_VOB_GI,SMLI, AGAPI, TMAPI, and CP_MNGI.

[0350] M_VOB_Gl (general information) (FIG. 16)

[0351] Records the following general information relating to a movieVOB.

[0352] VOB_TY (VOB type)

[0353] Stores VOB attributes according to the format as shown in FIG.17.

[0354] TE

[0355] Stores one of the following values indicating the VOB status.

[0356] 0b: normal

[0357] 1b: temporarily deleted condition

[0358] A0_STATUS

[0359] Stores one of the following values indicating the status of audiostream 0.

[0360] 00b: original state

[0361] 01b: overwritten

[0362] A1_STATUS

[0363] Stores one of the following values indicating the status of audiostream 1.

[0364] 00b: original state

[0365] 01b: overwritten

[0366] 10b: dummy for additional audio content

[0367] 11b: additional audio content added

[0368] SML_FLG

[0369] Stores one of the following values indicating whether the VOB isto be seamlessly reproduced with the preceding VOB.

[0370] 0b: seamless reproduction not possible

[0371] 1b: seamless reproduction possible

[0372] A0_GAP_LOC

[0373] Stores one of the following values indicating the presence of anaudio reproduction gap in audio stream 0, and identifying the VOBU towhich the audio reproduction gap is multiplexed.

[0374] 00b: no audio reproduction gap recorded

[0375] 01b: audio reproduction gap multiplexed to first VOBU

[0376] 10b: audio reproduction gap multiplexed to second VOBU

[0377] 11b: audio reproduction gap multiplexed to third VOBU

[0378] A1_GAP_LOC

[0379] Stores one of the following values indicating the presence of anaudio reproduction gap in audio stream 1, and identifying the VOBU towhich the audio reproduction gap is multiplexed.

[0380] 00b: no audio reproduction gap recorded

[0381] 01b: audio reproduction gap multiplexed to first VOBU

[0382] 10b: audio reproduction gap multiplexed to second VOBU

[0383] 11b: audio reproduction gap multiplexed to third VOBU

[0384] VOB_REC_TM (VOB recording date/time)

[0385] The date and time the VOB was recorded is stored in the sameformat used for PL_CREATE_TM shown in FIG. 9. What is important to notehere is that this indicates the dateltime that the first videopresentation frame of the VOB was recorded. If the first video frame ischanged by editing or deletion, this VOB_REC_TM value must be updated.It should be further noted that the date/time of recording can bedisplayed synchronized to the VOB presentation similarly to the way adate/time is displayed on the viewfinder of a video camcorder by simplyadding the time elapsed in the VOB to the time stored as VOB_REC_TM.

[0386] VOB_REC_TM_SUB (VOB recording date/time difference information)

[0387] This field is used to absorb error in a VOB_REC_TM field that hasbeen updated because the first video frame in the VOB was changed by VOBediting or deletion. As shown in FIG. 9, VOB_REC_TM is only accurate tothe second. This means that if the video was edited or deleted at theframe or field level (precision), the recording time cannot be expressedwith sufficient accuracy using only VOB_REC_TM. This field is thereforeused to adjust for any difference.

[0388] M_VOB_STIN (M_VOB_STI number)

[0389] Stores the M_VOB_STI number corresponding to the VOB. ThisM_VOB_STI number is the recording sequence in the above-noted M_VOB_STItable.

[0390] VOB_V_S_PTM (VOB video start PTM)

[0391] Stores the VOB presentation start time based on the samereference time as the time stamp of the video stream.

[0392] VOB_V_E_PTM (VOB video end PTM)

[0393] Stores the VOB presentation end time based on the same referencetime as the time stamp of the video stream. It should be noted that thetime stamp of the stream indicates the presentation start time of theframe, but this VOB_V_E_PTM field records the presentation end time,that is, the sum of the start time plus the frame presentation period.

[0394] SMLI (seamless information) (FIG. 16)

[0395] SMLI stores the following information required for seamlessreproduction with the preceding VOB. Note that this field is onlyrecorded when the above-noted SML_FLG is 1b.

[0396] VOB_FIRST_SCR

[0397] Stores the SCR of the first pack in the VOB.

[0398] PREV_VOB_LAST_SCR

[0399] Stores the SCR of the last pack in the previous VOB.

[0400] AGAPI (audio gap information) (FIG. 16)

[0401] AGAPI records the following information required for the decoderto process an audio reproduction gap. This field is only recorded when avalue other than 00b is written to the above-noted A0_GAP_LOC or A1_GAP_LOC.

[0402] VOB_A_STP_PTM (VOB audio stop PTM)

[0403] Records the time of the audio reproduction gap, that is, the timeat which the decoder is to temporarily stop audio reproduction. Thistime is recorded using the same reference time as the stream time stamp.

[0404] VOB_A_GAP_LEN (VOB audio gap length)

[0405] Records the length of the audio reproduction gap in 90 kHzprecision.

[0406] TMAPI (time map information) (FIG. 18)

[0407] The time map information comprises TMAP_Gl, TM_ENT, and VOBU_ENTfields.

[0408] TMAP_GI (FIG. 18)

[0409] The general TMAP information TMAP_GI comprises TM_ENT_Ns,VOBU_ENT_Ns, TM_OFS, and ADR_OFS fields as described below.

[0410] TM_ENT_Ns (TM_ENT number)

[0411] Records the number of TM_ENT fields in the TMAPI block asdescribed below.

[0412] VOBU_ENT_Ns (VOBU_ENT number)

[0413] Records the number of VOBU_ENT fields in the TMAPI block asdescribed below.

[0414] TM_OFS (time offset)

[0415] Records the time map offset with the video field precision.

[0416] ADR_OFS (address offset)

[0417] Records the offset in the first AV field in the VOB.

[0418] TM_ENT (time entry) (FIG. 18)

[0419] A time entry comprises the following fields as access pointinformation at a constant time interval TMU. If the video format isNTSC, the TMU is 600 video fields; if PAL, it is 500 video fields.

[0420] VOBU_ENTN (VOBU_ENT number)

[0421] Records the entry number of a VOBU containing the time (TMUx(N_(—)1)+TM_OFS for the N-th TM_ENT) indicated by the TM_ENT.

[0422] TM_DIFF (time difference)

[0423] Records the difference between the time indicated by this TM_ENTand the presentation start time of the VOBU pointed to by VOBU_ENTN.

[0424] VOBU_ADR (VOBU address)

[0425] Records the start address in the VOB of the VOBU pointed to byVOBU_ENTN.

[0426] VOBU_ENT (FIG. 19)

[0427] The VOBU entry (VOBU_ENT) has the fields shown below for thecorresponding VOBU. The fields are formatted as shown in FIG. 19. Thetime and address information required to access a desired VOBU can beobtained by simply adding the following fields in sequence.

[0428] 1STREF_SZ

[0429] Stores the number of packs from the first pack in the VOBU to thepack containing the last data block of the first I-picture in the VOBU.

[0430] VOBU_PB_TM

[0431] Records the playback time of this VOBU.

[0432] VOBU_SZ

[0433] Records the data size of this VOBU.

[0434] S_AVFIT (FIG. 20)

[0435] The still image AV file information table comprises the followingmanagement information fields for the still image AV file RTR_STILL.VRO:S_AVFITI, S_VOB_STI, S_AVFI.

[0436] S_AVFITI (still image AV file information table information)(FIG. 20)

[0437] Stores the following information required to access S_VOB_STI,S_AVFI, S_AASTI (FIG. 21), and S_AAFI (FIG. 21).

[0438] S_AVFI_Ns (still image AV file information number)

[0439] This is a value of either 0 or 1. This value corresponds to thenumber of still image AV files, that is, whether a RTR_STILL.VRO file ispresent.

[0440] S_VOB_STL_Ns (still image VOB stream information number)

[0441] Records the number of S_VOB_STI described below.

[0442] S_AVFI_EA (still image AV file information end address)

[0443] Records the S_AVFI end address.

[0444] S_VOB_STI (still image VOB stream information) (FIG. 20)

[0445] Records the following still image VOB stream information.

[0446] V_ATR (video attributes)

[0447] Information recorded as the video attributes are the Videocompression mode, TV system, Aspect ratio, and Video resolution. Thesefields are as described above with reference to the video attributes ofthe M_VOB_STI.

[0448] OA_ATR (audio stream attributes)

[0449] The audio stream attribute fields are: Audio coding mode,Application Flag, Quantization/DRC, fs, Number of Audio channels. Theseare also as described above with reference to the A_ATRO fields of theM_VOB_STI.

[0450] SP_PLT (subpicture color palette)

[0451] Stores the color palette information for subpictures. The formatis as described with reference to the SP_PLT of M_VOB_STI.

[0452] S_AVFI (still image AV file information) (FIG. 24)

[0453] Comprises the following fields required to access a still imageVOG: S_AVFI_GI, S_VOGI_SRP, and S_VOGI.

[0454] S_AVFI_GI (FIG. 24)

[0455] General still image AV file information S_AVFI_GI recordsS_VOGI_SRP_Ns.

[0456] S_VOGI_SRP_Ns (still image VOB group search pointer number)

[0457] Records the number of S_VOGI_SRP fields described below.

[0458] S_VOGI_SRP (still image VOB group information search pointer)(FIG. 24)

[0459] Records S_VOGI_SA.

[0460] S_VOGI_SA (still image VOB group information start address)records the start address of this S_VOGI.

[0461] S_VOGI (FIG. 24)

[0462] The still image VOB group information S_VOGI comprises thefollowing still image VOB management information fields: S_VOG_GI,S_VOB_ENT, and CP_MNGI.

[0463] S_VOG_GI (FIG. 24)

[0464] General still image VOB group information S_VOG_GI records thefollowing fields as general information relating to the still image VOBgroup.

[0465] S_VOB Ns (still image VOB number)

[0466] Records the number of still image VOBs in the still image VOBgroup.

[0467] S_VOB STIN (S_VOB_STI number)

[0468] Records the S_VOB_STI number storing the still image VOB streaminformation. This S_VOB_STI number is the recording sequence in theS_VOB_STI table.

[0469] FIRST VOB_REC_TM (first VOB recording date/time)

[0470] Records the recording date/time information of the first stillimage VOB in the still image VOB group.

[0471] LAST_VOB_REC_TM (last VOB recording date/time)

[0472] Records the recording date/time information of the last stillimage VOB in the still image VOB group.

[0473] S_VOB_SA (still image VOB group start address)

[0474] Records the start address of the still image VOB group in theRTR_STILL.VRO file.

[0475] S_VOB ENT (FIG. 25)

[0476] Still image VOB entries S_VOB_ENT are defined as either type A ortype B as described below according to whether there is audio recordedfor individual still image VOBs in the still image VOB group.

[0477] S_VOB_ENT (Type A) (FIG. 25)

[0478] Type A comprises the fields S_VOB_ENT_TY and V_PART_SZ, definedas follows.

[0479] S_VOB_ENT_TY (still image VOB entry type)

[0480] Still image VOB type information is formatted as shown in FIG.26. MAP_TY

[0481] Stores one of the following values for identifying type A or typeB.

[0482] 00b: type A

[0483] 01b: type B

[0484] TE

[0485] Stores one of the following values indicating the status of thestill image VOB.

[0486] 0b:.normal

[0487] 1b: temporarily deleted

[0488] SPST_Ns

[0489] Stores the number of subpicture streams in the still image VOB.

[0490] V_PART_SZ (video part size)

[0491] Stores the data size of the video part of the still image VOB.

[0492] S_VOB_ENT (Type B) (FIG. 25)

[0493] In addition to S_VOB_ENT_TY and V_PART_SZ fields, type B also hasA_PART_SZ and A_PB_TM fields as defined below.

[0494] S_VOB_ENT_TY (still image VOB entry type)

[0495] Records the type of the still image VOB. These fields are asdescribed above with reference to type A and FIG. 26.

[0496] V_PART_SZ (video part size)

[0497] Stores the data size of the video part of the still image VOB.

[0498] A_PART_SZ (audio part size)

[0499] Stores the data size of the audio part of the still image VOB.

[0500] A_PB_TM (audio playback time)

[0501] Stores the playback time (length) of the audio part of the stillimage VOB.

[0502] S_AAFI (FIG. 27)

[0503] The still image added audio file information comprises thefollowing information fields. S_AAFI_GI, S_AAGI_SRP, and S_AAGI.

[0504] S_MFI_GI (general information) (FIG. 27)

[0505] General information about still image added audio files containsthe following information.

[0506] S_AAGI_SRP_Ns (still image added audio group information number)

[0507] Records the number of S_AAGI_SRP fields in the S_AAFI block.

[0508] S_AAGI_SRP (FIG. 27)

[0509] Records the following information as a search pointer to thestill image added audio group information.

[0510] S_AAGI_SA (still image added audio group information startaddress)

[0511] Records the start address of the S_AAGI [S_AAGI_SA, sic] field inthe still image added audio file information.

[0512] S_AAGI (FIG. 28)

[0513] The still image added audio group information comprises thefollowing fields: S_AAG_GI and AA_ENT.

[0514] S_AAG_GI (FIG. 28)

[0515] The general still image added audio group information includesthe following fields.

[0516] AA_ENT_Ns

[0517] Records the number of AA_ENT fields in the still image addedaudio group.

[0518] S_AA_STIN (FIG. 21, FIG. 28)

[0519] Records the S_AA_STI number in the still image added audio group.

[0520] S_AAG_SA

[0521] Records the S_AAG start address in the still image added audiogroup.

[0522] AA_ENT (FIG. 28)

[0523] The added audio entry AA_ENT records the following fields.

[0524] AA_TY (FIG. 29)

[0525] Records the type of each added audio entry.

[0526] AA_PART_SZ

[0527] Records the size of the added audio entry.

[0528] AA_PART_PB_TM

[0529] Records the playback time the added audio entry.

[0530] UD_PGCIT (FIG. 30)

[0531] The user-defined PGC information table comprises the followingfields: UD_PGCITI, UD_PGCI_SRP, and UD_PGCI. UD_PGCITI (FIG. 30)

[0532] The user-defined PGC information table information UD_PGCITIrecords the following fields constituting the user-defined PGCinformation table.

[0533] UD_PGCI_SRP_Ns (user-defined PGC information search pointernumber)

[0534] Records the number of UD_PGCI_SRP fields.

[0535] UD_PGCIT_EA (user-defined PGC information table end address)

[0536] Records the UD_PGCIT end address.

[0537] UD_PGCI_SRP (FIG. 30)

[0538] The user-defined PGC information search pointer UD_PGCI_SRPrecords the UD_PGCI_SA field.

[0539] UD_PGCI_SA (user-defined PGC information start address)

[0540] Records the UD_PGCI start address. This address is used to seekand access the PGCI.

[0541] UD_PGCI (FIG. 30)

[0542] The detailed structure of the user-defined PGC information isdescribed further below under the PGC information PGCI.

[0543] ORG_PGCI (FIG. 5)

[0544] The detailed structure of the original PGC information isdescribed further below under the PGC information PGCI.

[0545] TXTDT_MG (FIG. 31)

[0546] The text data management field TXTDT_MG comprises TXTDTI,IT_TXT_SRP, and IT_TXT fields as described below.

[0547] TXTDTI (FIG. 31)

[0548] Text data information TXTDTI comprises the following fields:CHRS, IT_TXT_SRP_Ns, TXTDT_MG_EA.

[0549] CHRS (character set code)

[0550] Records the character set code used for IT_TXT.

[0551] IT_TXT_SRP_Ns (IT_TXT search pointer number)

[0552] Records the number of IT_TXT_SRP fields.

[0553] TXTDT_MG_EA (text data management end address)

[0554] Records the end address of the TXTDT_MG block.

[0555] IT_TXT_SRP (FIG. 31)

[0556] The IT_TXT search pointer IT_TXT_SRP records the followinginformation for accessing IT_TXT.

[0557] IT_TXT SA (IT TXT start address)

[0558] Records the IT_TXT start address. This address is used to seekand access the IT_TXT block.

[0559] IT_TXT_SZ (IT_TXT size)

[0560] Records the IT_TXT data size. A desired IT_TXT block can be readby reading this amount of data.

[0561] IT_TXT (FIG. 31)

[0562] IT_TXT comprises one or more sets of three fields: identificationcode IDCD, the text TXT corresponding to that ID code, and an end codeTMCD defining the end of the set. If there is no TXT field for an IDCD,the TXT field can be omitted and IDCD and TMCD recorded as one set.Valid IDCD values are defined as follow.

[0563] Genre codes

[0564] 30h: movie

[0565] 31h: music

[0566] 32h: drama

[0567] 33h: animation

[0568] 34h: sports

[0569] 35h: documentary

[0570] 36h: news

[0571] 37h: weather

[0572] 38h: educational

[0573] 39h: hobby

[0574] 3Ah: entertainment

[0575] 3Bh: performing arts (plays, opera)

[0576] 3Ch: shopping

[0577] Input source codes

[0578] 60h: broadcasting station

[0579] 61h: camcorder

[0580] 62h: photograph

[0581] 63h: memo

[0582] 64h: other

[0583] PGCI (FIG. 32)

[0584] PGCI (PGC information) is common to both ORG_PGCI and UD_PGCI,and comprises the following fields: PGC_GI, PGI, CI_SRP, CI.

[0585] PGC_GI (FIG. 32)

[0586] PGC_GI (PGC general information) comprises the fields PG_Ns andCI_SRP_Ns as general information about the PGC.

[0587] PG_Ns (program number)

[0588] Records the number of programs in the PGC. If a user-defined PGC,this field is 0 because there is no program.

[0589] CI_SRP Ns (CI_SRP number)

[0590] Records the number of CI SRP, described below.

[0591] PGI (FIG. 32)

[0592] PGI (program information) comprises the following fields asdescribed below: PG_TY, C_Ns, PRM_TXTI, IT_TXT_SRPN, THM_PTRI.

[0593] PG_TY (program type)

[0594] Records the following information formatted as shown in FIG. 33.

[0595] Protect (protected)

[0596] 0b: normal

[0597] 1b: protected

[0598] C_Ns (cell number)

[0599] Records the cell number in the program.

[0600] PRM_TXTI (primary text information)

[0601] Records the text information describing program content. Forfurther details, see the above-noted PL_SRPT. IT_TXT_SRPN (IT_TXT_SRPnumber)

[0602] If IT_TXT containing program content information is recorded inaddition to the primary text noted above, the IT_TXT_SRP number recordedin TXTDT_MG is stored to this field.

[0603] THM_PTRI (thumbnail image pointer information)

[0604] Records the thumbnail image information representing thisprogram. Details about the THM_PTRI are identical to the above-notedTHM_PTRI of PL_SRPT.

[0605] CI_SRP (FIG. 32)

[0606] The cell information search pointer (CI_SRP) records addressinformation required for accessing this cell information.

[0607] CI_SA (cell information start address)

[0608] Records the start address of the cell information. The cell isaccessed by seeking this address.

[0609] CI (FIG. 32)

[0610] CI (cell information) is one of two types: M_CI for movies, orS_CI for still image.

[0611] M_CI (FIG. 34)

[0612] M_CI (movie cell information) comprises the following fields:M_C_GI and M_C_EPI.

[0613] M_C_GL (FIG. 34)

[0614] M_C_GI (movie cell general information) contains the followingbasic information for each cell.

[0615] C_TY (cell type)

[0616] Records the following information formatted as shown in FIG. 35for identifying movie cells and still image cells.

[0617] C_TY1

[0618] 000b: movie cell

[0619] 001b: still image cell

[0620] M_VOBI_SRPN (movie VOB information search pointer number)

[0621] Records the search pointer number of the movie VOB informationcorresponding to this cell. To access the stream data corresponding tothis cell, it is first necessary to access the movie VOB informationsearch pointer number indicated by this field.

[0622] C_EPI_Ns (cell entry point information number)

[0623] Records the number of an entry point to this cell.

[0624] An entry point is an address in the reproduction path which canbe used in a seek operation to find a specific point from whichreproduction is to commence. If entry points are used and playbackadvances to an entry point in the reproduction path, playback can jumpto the recorded absolute address and continue reproduction therefrom,thereby enabling a reproduction path to skip from point to point. Theseentry points can be set as desired in the reproduction stream in amanner similar to marking a page in a book with a bookmark so that ifreproduction is interrupted it can be resumed as desired from aparticular location.

[0625] C_V_S_PTM (cell video start time)

[0626] Records the playback start time of the cell using the formatshown in FIG. 10.

[0627] C_V_E_PTM (cell video end time)

[0628] Records the playback end time of the cell using the format shownin FIG. 10. Used in conjunction with C_V_S_PTM and C_V_E_PTM to definethe cell period within the corresponding VOB.

[0629] M_C_EPI (FIG. 36)

[0630] M_C_EPI (movie cell entry point information) is categorized asType A or Type B based on the presence of primary text.

[0631] M_C_EPI (Type A) (FIG. 36)

[0632] M_C_EPI (Type A) contains the following information indicative ofan entry point.

[0633] EP_TY (entry point type)

[0634] Records the following information formatted as shown in FIG. 37for identifying the entry point type.

[0635] EP_TY1

[0636] 00b: Type A

[0637] 01b: Type B

[0638] EP_PTM (entry point time)

[0639] Records the time at which the entry point is set according to theformat as shown in FIG. 10.

[0640] M_C_EPI (Type B) (FIG. 36)

[0641] In addition to the same EP_TY and EP_PTM fields of Type A,M_C_EPI (Type B) has a PRM_TXTI field as described below.

[0642] PRM_TXTI (primary text information)

[0643] Records text information describing the content of the locationindicated by the entry point. Details of this information are asdescribed in the above-noted PL_SRPT.

[0644] S_CI (FIG. 34)

[0645] S_CI (still image cell information) comprises S_C_GI and S_C_EPIfields.

[0646] S_C_GI (FIG. 34)

[0647] S_C_GI (still image cell general information) contains the basiccell information described below.

[0648] C_TY (cell type)

[0649] Records information for identifying movie cells and still imagecells. This cell type information is as described above with referenceto a movie cell.

[0650] S_VOGI_SRPN (still image VOB group information search pointernumber)

[0651] Records the search pointer number of the still image VOB groupinformation for the cell. To access the stream data corresponding to thecell, it is first necessary to access the still image VOB groupinformation search pointer number indicated by this field.

[0652] C_EPI_Ns (cell entry point information number)

[0653] Records the number of an entry point in this cell.

[0654] S_S_VOB_ENTN (starting still image VOB number)

[0655] Records the still image VOB number from which cell reproductionstarts according to the format as shown in FIG. 11. The still image VOBnumber is the sequence number in the S_VOG pointed to by the above-notedS_VOGI_SRPN.

[0656] E_S_VOB_ENTN (end still image VOB number)

[0657] Records the still image VOB number at which cell reproductionends according to the format as shown in FIG. 11. The still image VOBnumber is the sequence number in the S_VOG pointed to by the above-notedS_VOGI_SRPN. It should be noted that the valid cell period in the S_VOGto which the cell belongs is defined by this field in conjunction withS_S_VOB_ENTN and E_S_VOB_ENTN.

[0658] S_C_EPI (FIG. 36)

[0659] S_C_EPI (still image cell entry point information) is categorizedas Type A or Type B depending upon the presence of primary text.

[0660] S_C_EPI (Type A) (FIG. 36)

[0661] S_C_EPI (Type A) contains the following information indicative ofan entry point.

[0662] EP_TY (entry point type)

[0663] Records the following information formatted as shown in FIG. 37for identifying the entry point type.

[0664] EP_TY1

[0665] 00b: Type A

[0666] 01b: Type B

[0667] S_VOB_ENTN (still image VOB entry number)

[0668] Records the still image number in which the entry point is setaccording to the format as shown in FIG. 11.

[0669] S_C_EPI (Type B) (FIG. 36)

[0670] In addition to the same EP_TY and S_VOB_ENTN fields of Type A,S_C_EPI (Type B) has a PRM_TXTI as described below.

[0671] PRM_TXTI (primary text information)

[0672] Records text information describing the content of the locatedindicated by the entry point. Details of this information are asdescribed in the above-noted PL_SRPT.

[0673] Entry Points and Management Information

[0674] The relationship between entry points and management informationis described next with reference to FIG. 44. As noted above, there aretwo types of AV data: M_VOB and S_VOB.

[0675] M_VOB has M_VOBI management information for each M_VOB. M_VOBIrecord attributes about the corresponding M_VOB.

[0676] Attempting to manage S_VOB with management information recordedfor each individual S_VOB [S_VOG, sic] would significantly increase theamount of management information stored. A number of S_VOB are thereforecombined in S_VOB groups (S_VOG), which are then managed usingmanagement information S_VOGI. The S_VOGI stores attributes for theS_VOB group.

[0677] Plural entry points can be set for the movie cells correspondingto an individual M_VOB with the M_C_EPI (movie cell entry pointinformation) recorded in M_CI. As described above, M_C_EPI is eitherType A or Type B depending on the presence of primary text. If Type A,the entry point time (EP_PTM), that is, the time at which the entrypoint is set, is recorded with the entry point type (EP_TY). If Type B,text information (PRM_TXT) describing the content of the addressindicated by the entry point is recorded in addition to the informationrecorded for Type A.

[0678] Using the recorded entry point time (EP_PTM) and filter TMAP forconverting time and address information in the M_VOBI, the time at whichthe entry point is placed can be converted to an M_VOB address. The TMAPrecords the size of the VOBU corresponding to this time, and playbacktime information. This information can thus be used to calculate theaddress of the corresponding M_VOB.

[0679] A method for converting time information to an address using thisTMAP is taught in detail in Japanese Unexamined Patent Application(kokai) 11-155130 (EU Patent 0 903 738 A2), the content of which iscontained herein by reference.

[0680] Plural entry points can be set for the still image cellscorresponding to an individual S_VOB with the S_C EPI (still image cellentry point information) recorded in S_CI. As described above, S_C_EPIis either Type A or Type B depending on the presence of primary text. IfType A, the still image VOB number S_VOB_ENTN is recorded with the entrypoint type (EP_TY). If Type B, text information (PRM_TXT) describing thecontent of the address indicated by the entry point is recorded inaddition to the information recorded for Type A.

[0681] The time at which the entry point is set can be converted to anS_VOB address using the recorded still image VOB number S_VOB_ENTN inconjunction with the filter S_VOB Entries for converting an address andstill image number in the still image VOB group of the S_VOBI. S_VOBEntries records the Video Part size, which can be used to calculate theaddress of the Video Part contained in the corresponding still image VOBgroup.

[0682] As shown in FIG. 45, when plural reproduction paths are present,such as the user-defined PGC indicated by Play List #1 and Play List #2,it is still possible to set a plurality of entry points for each moviecell or still image cell.

[0683] If plural entry points are set for each M_VOB movie cell, theM_C_EPI (movie cell entry point) field is recorded to M_CI.

[0684] If plural entry points are set for each S_VOB still image cell,the S_C_EPI (still image cell entry point) field is recorded to S_CI.

[0685] The part shown as the program set in FIG. 45 corresponds to theoriginal program information (ORG_PGCI), and program #1 corresponds toPGI#1 of ORG_PGCI in FIG. 34. Play list #1 also corresponds to UD_PGCIPGI#1 in FIG. 34. The solid black triangles in FIG. 45 indicate entrypoint positions, the triangles at the M_Cell corresponding to M_C_EPI#1and #2 in FIG. 34, and the triangles at the S_Cell corresponding toS_C_EPI#1 and #2 in FIG. 34.

[0686] M_Cell contains information indicating from and to where in theM_VOBI block to reproduce. S_Cell contains information indicating whichstill image in the S_VOBI (still image VOB information) to reproduce.

[0687] A program for reproducing the program stream in the sequencerecorded is set in the original program information (ORG PGCI). Playlist #1 and #2 define a group of cells and a reproduction sequence asdefined by the user. The time at which a particular cell is reproduced,that is, the presentation time, will thus vary for cells in the sameprogram stream depending on whether the original program #1, play list#1, or play list #2 is reproduced. It will thus be obvious that thereproduction sequence can be changed, and parts of a program stream canbe effectively deleted, by applying user-defined play lists to a sameprogram stream. In other words, plural reproduction paths can bedefined.

[0688] In addition, an entry point set for an M_VOB in original program#1 (referred to as a first entry point) is managed by the originalprogram management information (ORG_PGCI), and an entry point (secondentry point) set for the same M_VOB but associated with play list #1 ismanaged by the management information UD_PGCI of the play list #1.Therefore, when the program stream is reproduced according to program#1, only the first entry point operates as a valid entry point, and thesecond entry point is not used. Likewise when reproducing play list #1,only the second entry point operates as a valid entry point, and thefirst entry point is not used. It is thus possible as indicated by theblack triangles in FIG. 45 to independently set entry points for each ofplural reproduction paths.

[0689] The hierarchical structure of the ORG_PGCI management informationis shown in FIG. 5, FIG. 32, and FIG. 34.

[0690] The hierarchical structure of the UD_PGCI management informationis shown in FIG. 5, FIG. 30, FIG. 32, and FIG. 34. It should be notedthat UD_PGCIT (user defined program chain information table) is shown inFIG. 5 because there can be plural UD_PGCI. A UD_PGCI table is thereforeprovided so that a desired single UD_PGCI can be selected.

[0691] The S_VOGI (Still Video Object Group Information) and moviemanagement information M_VOBI are shown in row L2 of FIG. 45. A maximum999 M_VOBI blocks can be created on an optical disc. The hierarchicalstructure of this M_VOBI management information is shown in FIG. 5, FIG.15, and FIG. 16.

[0692] It can be determined by reading the management informationdescribed next below in the sequence indicated by steps S1 to Sn whethera cell in the row L1 program chain information PGCI is associated withany M_VOBI management information for movies on row L2.

[0693] S1 in FIG. 5→S2→S4 in FIG. 32 (C_Ns is the number of cells in theprogram. The number of the cell contained in the desired program isobtained by counting from the first program. The number of the obtainedcell is used as the cell search pointer CI_SRP#n.)

[0694] →S5→S6→S7 (Obtain the cell address based on the cell searchpointer.)

[0695] →S8 (Obtain the number of the address cell information.)

[0696] →FIG. 34, S9 (movie cell information M_CI)

[0697] →S10 (movie cell general information M_CGI.)

[0698] →S11 (movie VOB information search pointer number M_VOBI_SRPN)

[0699] →FIG. 5, S12 (AV file information table)

[0700] →FIG. 15, S13→S14→S15 (access the movie VOB information searchpointer detected in S11)

[0701] →S16→S17 (determine the movie VOB information start address)

[0702] →S18→19 (Step #495 in FIG. 49)

[0703] The start presentation time (VOB_V_S_PTM) of the movie can bedetermined from the movie VOB information M_VOBI in FIG. 18 using TMAP(S20) and TMAP_BI (S21).

[0704] Configuration of a DVD Recorder

[0705] The configuration of a DVD recorder is described next below withreference to FIG. 46.

[0706] As shown in the figure, this DVD recorder comprises a userinterface 7801 for interaction with the user; a system controller 7802for handling overall management and control of the recorder; an inputblock 7803 comprising an AD converter for audio and video input to therecorder; an encoder 7804; an output section 7805 for audio and videooutput; a decoder 7806 for MPEG stream decoding; track buffer 7807; anddrive 7808.

[0707] Operation of a DVD Recorder

[0708] An entry point reproduction operation using entry points isdescribed next below.

[0709] When the user interface 7801 receives a entry point play requestfrom the user requiring access to an entry point, it posts an entrypoint play request to the system controller 7802. The system controller7802 then performs the following steps.

[0710] A. To Play a Movie

[0711] (1) If an optical disc is in the disc player, the systemcontroller 7802 reads and stores the management information containingthe entry point information from the disc.

[0712] (2) The system controller 7802 reads address informationindicating the current playback position from the decoder 7806.

[0713] (3) The system controller 7802 converts this address informationto time information TO (in broad terms, a point) in the reproductionpath.

[0714] (4) The system controller 7802 then compares this timeinformation TO with the time list (time EP_PTM recorded to M_C_EPI#1, #2. . . #n in FIG. 30), that is, the entry point information group in themanagement information. If forward playback is in progress, the systemcontroller 7802 selects the entry point that is greater than (laterthan) time information T0 and is closest to T0 in the entry point timelist. If reverse playback is in progress, the system controller 7802selects the entry point that is lower (earlier) than and closest to T0.

[0715] (5) The system controller 7802 converts the time obtained fromthe time list to address information.

[0716] (6) The system controller 7802 instructs the drive 7808 to jumpfrom the current playback position to the position identified by theconverted address information.

[0717] (7) The system controller 7802 instructs the decoder 7806 todecode and output this new playback position to which the drive 7808just jumped.

[0718] B. To Play Back

[0719] (1) If an optical disc is in the disc player, the systemcontroller 7802 reads and stores the management information containingthe entry point information from the disc.

[0720] (2) The system controller 7802 reads address informationindicating the current playback position from the decoder 7806.

[0721] (3) The system controller 7802 converts the address informationto still image number information S0, that is, address information inthe program stream. This still image number information S0 indicates thesequence number of the still image currently being reproduced in thereproduction path.

[0722] (4) The system controller 7802 compares the converted still imagenumber information S0 with the still image number list (still imagenumber S_VOB_ENTN (FIG. 36) recorded in S_C_EPI#1, #2 . . . #n (FIG.30), that is, entry point information in the management information. Ifforward playback is in progress, the system controller 7802 selects thestill image with a still image number next greater than still image i snumber information S0 from the still image number list of entry points.If in reverse playback, it selects the still image with a still imagenumber next lower than still image number information S0 from the stillimage number list of entry points.

[0723] (5) The system controller 7802 converts the still image numberselected from the still image number list to address information.

[0724] (6) The system controller 7802 instructs the drive 7808 to jumpfrom the current playback position to the position identified by theconverted address information.

[0725] (7) The system controller 7802 instructs the decoder 7806 todecode and output this new playback position to which the drive 7808just jumped.

[0726] The process whereby the system controller 7802 converts an entrypoint to a VOB address during reproduction using an entry point isdescribed next with reference to FIG. 47 and FIG. 48.

[0727] The system controller 7802 requires an entry point number as wellas PGC number and cell number information to set an entry point (FIG. 49#492).

[0728] Next, the system controller 7802 detects whether the cellcontaining the entry point specified in the cell information entered bythe user by way of the user interface 7801 is a movie cell M_Cell orstill image cell S_Cell (FIG. 49 #493).

[0729] If reproduction from an entry point in a movie cell M_Cell isspecified, the system controller 7802 converts the time at which theentry point is set to an M_VOB address using the filter TMAP forconverting a time in an M_VOBI to an address (FIG. 47).

[0730] A process for converting a time to a movie VOB address isdescribed next below with reference to FIG. 49.

[0731] The first step in this process is to read the entry point timeEP_PTM (formatted as shown in FIG. 36) recorded to the movie cell entrypoint information M_C_EPI obtained from the specified entry point(#494). The system controller 7802 then retrieves the correspondingmovie VOB information search pointer number M_VOBI_SRPN from the moviecell information M_CI specified by the cell number, and detects thesearch pointer number of the movie VOB information for the cell (#495).

[0732] The system controller 7802 then obtains the corresponding M_VOBIfrom M_VOBI_SRPN, and using the TMAP filter in M_VOBI obtains the EP_PTMdetected in #494 as the address of a specific location in M_VOB. (#496).

[0733] The drive then accesses the detected address, and beginsreproduction therefrom (#500). It is therefore possible to startplayback from the entry point.

[0734] If playback from an entry point in a still image cell S_Cell isspecified, the DVD recorder converts the S VOB in which the entry pointis set to an S_VOB address using the S_VOB Entries filter for convertingthe still image number and address information of the S_VOBI within thegroup FIG. 48).

[0735] A process for converting a time to a still image VOB address isdescribed next below with reference to FIG. 49.

[0736] The first step in this process is to read the still image VOBentry number S_VOB_ENTN (formatted as shown in FIG. 36) recorded to thestill image entry point information S_C_EPI obtained from the specifiedentry point (#497). The system controller 7802 then retrieves thecorresponding still image VOB group information search pointer numberS_VOGI_SRPN from the still image cell information S_CI specified by thecell number, and detects the search pointer number of the still imageVOB group information for the cell (#498).

[0737] The system controller 7802 then obtains S_VOB Entriescorresponding to S_VOGI_SRPN, calculates the video part size V_PART_SZto the S_VOB_ENTN detected in #497, and converts the time where theentry point is set to a still image VOB address (#499).

[0738] The drive then accesses the detected address, and beginsreproduction therefrom (#500). It is therefore possible to startplayback from the entry point. By thus converting entry pointinformation to address information, the DVD recorder is able to useentry points set in the bitstream to begin playback from any desiredpoint in the reproduction path.

[0739] Referring to FIG. 46, the system controller 7802 requests thedrive 7808 to begin reading the stream based on address informationconverted from the disc, and instructs the decoder 7806 to decode andoutput the stream thus read.

[0740] The drive 7808 thus reads the stream from DVD-RAM and passes thestream to the track buffer 7807.

[0741] The decoder 7806 reads the stream from the track buffer, decodesthe stream, and passes the decoded stream to output section 7805.

[0742] The output section 7805 then outputs the decoded video and audioto the monitor (screen) and speakers.

[0743] A method for jumping reproduction to a desired point in areproduction path containing still images with no accompanying audio isdescribed next with reference to FIG. 50.

[0744] The playback time is not specified for still images with noaccompanying audio. The playback time in this case is determined bySTILL_TM or by user operations. A particular entry point therefore doesnot necessarily always indicate the same time (presentation time).Therefore, even if “00:07:50” is specified as the playback start time(FIG. 50), image “A” is not necessarily the image displayed becauseimage “B” may still be displayed depending on any change in the value ofSTILL_TM.

[0745] On the other hand, an entry point is contained in a cell, and istherefore not affected by the playback time of the reproduction path.Playback from the same entry point is therefore always possible even ifthe playback time or playback end time of the part of the bitstreamother than the cell containing the specified entry point changes as aresult of the STILL_TM value or user operations.

[0746] A high speed search (entry point skip) operation using theseentry points is described next with reference to FIGS. 46, 51, and 52.

[0747] When the system controller 7802 performs a high speed search(such as to skip commercials) during stream reproduction (FIG. 46), itcompares the current playback time with the time at which an entry pointis set, and searches for the closest future entry point from the currenttime. The system controller 7802 then converts the entry point resultingfrom this search to a VOB address, requests the drive 7808 to beginreading the bitstream from the disc based on this converted addressinformation, and requests the decoder 7806 to decode and output thestream.

[0748] The drive 7808 thus reads the bitstream from DVD-RAM, and outputsthe bitstream to the track buffer 7807.

[0749] The decoder 7806 thus reads and decodes the bitstream from thetrack buffer, and outputs the decoded stream to the output section 7805.

[0750] The output section 7805 then outputs the decoded video and audioto the display monitor and speakers.

[0751] The operation of the system controller during a high speed searchusing these entry points is described next with reference to FIG. 52.

[0752] The system controller 7802 receives from a user or disc player arequest to jump to the next entry point (#521).

[0753] The system controller 7802 thus detects the address of the VOBcurrently being reproduced from the decoder 7806 (#522).

[0754] The system controller 7802 converts the VOB address to a time todetermine the current time (#523).

[0755] Next, the system controller 7802 obtains a table of entry pointsin the cell being reproduced, and compares the current time with theentry point times in the table to retrieve the closest future entrypoint from the current time (#524, #525).

[0756] The system controller 7802 then jumps to and starts playback fromthe retrieved entry point according to the entry point playbackprocedure described above with reference to FIGS. 47, 48, and 49 (#526).

[0757] A DVD recorder can thus perform a high speed search such as onefor skipping commercials by using entry points as described above.

[0758] An entry point recording operation is described next below withreference to FIGS. 46 and 53.

[0759] When the user interface 7801 receives a user request to set anentry point at a particular time, it requests the system controller 7802to perform an entry point setting process.

[0760] The system controller 7802 generates and stores a time at whichto set an entry point in the movie cell M_Cell or still image cellS_Cell corresponding to the M_VOB or S_VOB in which the entry point isto be set.

[0761] If the entry point is to be set to a movie cell M_Cell, thesystem controller 7802 adds movie cell entry point information M_C_EPIto the corresponding movie cell information M_CI, and generates andstores the entry point type EP_TY and entry point time EP_PTM. If theentry point type is M_C_EPI Type B shown in FIG. 36, text informationPRM_TXT is also generated and stored.

[0762] If the entry point is to be set to a still image cell S_Cell, thesystem controller adds still image entry point information S_C_EPI tothe corresponding still image cell information S_CI, and generates andstores the entry point type EP_TY and still image VOB entry numberS_VOB_ENTN. If the entry point type is S_C_EPI Type B shown in FIG. 36,text information PRM_TXT is also generated and stored.

[0763] The entry point information stored by the system controller 7802is then recorded to the optical disc as part of the managementinformation.

[0764] System controller operation for entry point recording isdescribed next with reference to FIG. 53.

[0765] The system controller 7802 obtains the VOB address currentlybeing reproduced or recorded from the decoder (during playback) orencoder (during recording) (#532).

[0766] Next, the system controller 7802 converts this VOB addressinformation to time information or a specific still image number todetect the current time information or still image number information(#533). The TMAP information and VOB Entries information arecontinuously generated as necessary even during bitstream encoding. Itis therefore possible to convert the detected VOB address information totime or image number information and obtain the current time or imagenumber.

[0767] Finally, the system controller 7802 additionally records entrypoint information to the movie cell information M_CI or still image cellinformation S_CI corresponding to the M_VOB or S_VOB for which an entrypoint is to be set (#534). This results in entry point time EP_PTM beingnewly recorded to movie cell information M_CI, and still image VOB entrynumber S_VOB_ENTN, that is, the sequential still image number, beingnewly recorded to still image cell information S_CI. It should be notedthat this recording step refers to the entry point information beingtemporarily stored by system controller 7802 and recorded to opticaldisc in the management information format.

[0768] A DVD recorder is thus enabled by the above described process torecord entry points.

[0769] Screen Display

[0770]FIG. 54 is used to describe a typical screen display using entrypoints.

[0771] Two reproduction paths are shown on screen, “third grade fieldday” and a separate “fifth grade field day,” each having a plurality ofentry points set therein. It is therefore possible for a user to selectany one of plural entry points, each having logical meaning, from whichto start playback so that playback in each case starts from a meaningfulplace in the bitstream.

[0772] If the entry point is of Type B, it is also possible to displaytext, such as “100 m sprint” or “rooting fans.” In this case the usercan select the playback starting point by referring not only to timeinformation but also to text indicative of the bitstream content, thusmaking it even easier to select the point from which to start playback.

[0773]FIG. 55 shows a further exemplary screen display using informationabout the cells for which an entry point is set.

[0774] Information about the entry points recorded to the reproductionpath is displayed on screen. The type of cell for which an entry pointis set is indicated by the labels “M” for movie cell and “S” for stillimage cell. The user is thus able to know whether the image for whicheach entry point is set is a movie or still image.

[0775] It should be noted that the present invention has been describedwith reference to DVD-RAM media. It will be also obvious, however, thatentry points can be similarly set using other types of media, and thepresent invention shall therefore not be limited to DVD-RAM discs oreven to optical discs.

[0776] It should be noted that movie VOBs and still image VOBs arerecorded to AV files separately from other VOBs in the preferredembodiment described above, but these can also be recorded with othertypes of VOBs to the same AV file.

[0777] In addition, the present invention shall not be limited to the AVfile structure described above.

[0778] Benefits of the Invention

[0779] An optical disc or other random access capable data storagemedium for recording at least moving picture data is recorded withinformation about a plurality of reproduction paths for each of which isrecorded a plurality of entry points.

[0780] It is therefore possible to use a plurality of entry points foreach reproduction path, and thereby achieve random accessibility, afeature of disc media that tape media does not have, in each of aplurality of reproduction paths each having logical meaning.

[0781] Although the present invention has been described in connectionwith the preferred embodiments thereof with reference to theaccompanying drawings, it is to be noted that various changes andmodifications will be apparent to those skilled in the art. Such changesand modifications are to be understood as included within the scope ofthe present invention as defined by the appended claims, unless theydepart therefrom.

What is claimed is:
 1. An optical disc for recording a program stream ofaudio-visual content, original program management information formanaging reproduction of the program stream, a time-address conversiontable converting the reproduction time and address for a moving picture,and a number-address conversion table converting the number of a stillimage and an address on the optical disc for the still image, wherein,when the program stream contains a moving picture, said original programmanagement information containing: first start time informationrepresenting a start time of the moving picture from which thereproduction of the original program starts; first end time informationrepresenting an end time of moving picture at which the reproduction ofthe original program ends; and first entry point information to be setfor the program stream, said first entry point information comprisingfirst time information representing time at which the moving picturecontained in the original program is reproduced, and wherein, when theprogram stream contains a plurality of still images, said originalprogram management information containing: first start numberinformation representing a start number of a still image from which thereproduction of the original program starts; first end numberinformation representing an end number of a still image at which thereproduction of the original program ends; and first entry pointinformation to be set for the program stream, said first entry pointinformation comprising first number information representing a number ofa still image contained within the program stream.
 2. An optical disc asdescribed in claim 1 for further recording play list managementinformation for managing reproduction of at least a part of the programstream, which contains a moving picture, said play list managementinformation containing: second start time information representing astart time of the moving picture from which the reproduction of saidpart of the program stream starts; second end time informationrepresenting an end time of the moving picture at which the reproductionof said part of the program stream ends; and second entry pointinformation to be set for said part of the program stream, said secondentry point information comprising second time information representingtime at which the moving picture contained in said part of the programstream is reproduced.
 3. An optical disc as described in claim 1 forfurther recording play list management information for managingreproduction of a part of the program stream, which contains a pluralityof successive still images, said play list management informationcontaining: second start number information representing a start numberof a still image from which the reproduction of said part of the programstream starts; second end number information representing an end numberof a still image at which the reproduction of said part of the programstream ends; and second entry point information to be set for said partof the program stream, said second entry point information comprisingsecond number information representing a number of a still imagecontained within said part of the program stream.
 4. An optical disc asdescribed in claim 1 , wherein said entry point information furthercomprises text information representing contents of at least one of themoving picture and the still image with respect to said entry pointinformation.
 5. An optical disc as described in claim 11 wherein datasize of said first entry point information is larger than that of saidsecond entry point information.
 6. An optical disc as described in claim1 , wherein, when the program stream contains a moving picture, theprogram stream contains a plurality of video object units, each unitizedbased on reproduction time, and wherein said time-address conversiontable defines a relationship between said reproduction time and datasize of each of said plurality of video object unit.
 7. An optical discas described in claim 1 , wherein, when the program stream containsstill images, said number-address conversion table defines arelationship between the number and the data size of each of the stillimages.
 8. An optical disc player for reproducing an optical disc asdescribed in claim 1 , comprising: a storage means for reading andstoring the entry point information from the optical disc; a decoder fordecoding the program stream and generating address information duringprogram stream reproduction; a conversion means for converting theaddress information to point information in the program stream; aselection means for selecting entry point information closest to thepoint information; a conversion means for converting the selected entrypoint information to address information using at least one of saidnumber-address conversion table and said time-address conversion table;and a drive means for jumping to a location based on the convertedaddress information, wherein the decoder decodes and reproduces from thejump destination.
 9. An optical disc player as described in claim 1 ,wherein the point information is time information when the programstream is moving picture content.
 10. An optical disc player asdescribed in claim 1 , wherein the point information is still imagenumber information when the program stream is still image content. 11.An optical disc player as described in claim 1 , wherein the entry pointinformation further comprises text information, and the decoder furtherreproduces the text information.
 12. An optical disc playback method forplaying back an optical disc as described in claim 1 , comprising thesteps of: reading and storing the entry point information from theoptical disc; decoding the program stream and generating addressinformation during program stream reproduction; converting the addressinformation to point information in the program stream using at leastone of said number-address conversion table and said time-addressconversion table; selecting entry point information closest to the pointinformation; converting the selected entry point information to addressinformation; jumping to a location based on the converted addressinformation, and decoding and reproducing from the jump destination. 13.An optical disc recorder for recording to an optical disc as describedin claim 1 comprising: an interface for receiving entry pointinformation input; means for generating address information at the timethe entry point information is received; a conversion means forconverting the address information to entry point information in theprogram stream using at least one of said number-address conversiontable and said time-address conversion table; a storage means fortemporarily storing the entry point information; and a drive means forrecording the stored entry point information to the optical disc.
 14. Anoptical disc recorder as described in claim 13 , wherein the pointinformation is time information when the program stream is movingpicture content.
 15. An optical disc recorder as described in claim 13 ,wherein the point information is still image number information when theprogram stream is still image content.
 16. An optical disc recorder asdescribed in claim 13 , wherein the entry point information furthercomprises text information, and the storage means generates and storessaid text information.
 17. An optical disc recording method forrecording to the optical disc as described in claim 1 comprising thesteps of: receiving entry point information input; generating addressinformation at the time the entry point information is received;converting the address information to entry point information in theprogram stream using at least one of said number-address conversiontable and said time-address conversion table; temporarily storing theentry point information; and recording the stored entry pointinformation to the optical disc.